1. Field of the Invention
The present invention relates to a portable terminal, and more particularly to a sliding module for a sliding-type portable terminal, wherein a pair of housings are coupled in a manner such that they can slide in a longitudinal direction in order to open or close in a sliding motion.
2. Description of the Related Art
In general, current conventional portable terminals may be classified into various types according to their appearance, such as bar-type portable terminals, flip-type portable terminals and folder-type portable terminals.
The bar-type portable terminal has a single main housing, which is provided with a data input/output device, a transceiver unit and a receiver unit. This type is limited with regard to compactness, which results from constant exposure of the keypad, i.e., a data input means, as well as ensuring a sufficient distance between the transceiver unit and the receiver unit.
The flip-type portable terminal includes a body, a flip and a hinge device which pivotably connects the body to the flip. The body is provided with a data input/output device, a transceiver unit and a receiver unit. The flip opens or closes the key pad (i.e. data input means), thereby preventing a malfunction of the portable terminal. However, the flip-type portable terminal is also limited in compactness due to ensuring the distance between the transceiver unit and the receiver unit.
The folder-type portable terminal has a body, a folder, and a hinge device, which pivotably connect the body with the flip, and the folder can open/close by pivoting. This type is advantageous in compactness since the malfunction of a keypad can be avoided in a telephone call standby mode, i.e., when the folder is closely contacted to the body, and the folder can sufficiently ensure a distance between the transceiver unit and the receiver unit in a telephone call mode. This has led to such folder-type portable terminals being widely used as a main portable terminal.
With diversification of the designs of portable terminals, however, a sliding-type portable terminal, wherein a pair of housings are coupled in a manner that they can slide to be opened/closed through sliding motions, have been developed and commercialized. The sliding-type portable terminal is advantageous in compactness as well as in portability, which corresponds with that of the folder-type portable terminal. As a result, the sliding-type portable terminal is expected to make great inroads into the market occupied by the folder-type portable terminal.
U.S. Pat. No. 6,822,871, commonly assigned to the Assignee of the present invention and issued on Nov. 23, 2004, discloses a construction of such a sliding-type portable terminal. Since the sliding-type portable terminal described therein utilizes a sliding module with torsion springs, it performs a semi-automatic sliding motion. In particular, when a pair of housings are coupled in a manner that they can slide along each other, either one of two housings starts to be slid by user's manipulation in one section. Thereafter, the other housing is automatically slid by the driving force of the torsion spring in the other section.
However, the conventional sliding-type portable terminal is a sliding module, which utilizes a driving force of the torsion spring. Therefore, when the driving force for opening/closing the portable terminal is provided, there may exist a limitation with regard to compactness due to a problem in ensuring a space for the movement of the torsion springs. In particular, in order to ensure the space for the movement of the torsion springs, there is great restriction to reduce the width of the sliding module and that of the portable terminal.